Mixtures of azines and polyphenyl ethers as functional fluids



United States Patent 14,063/ 65 US. Cl. 252-515 4 Claims Int. Cl. Clflm l/32 ABSTRACT OF THE DISCLOSURE Improved functional fluids comprising a synergistic mixture of (a) a polyalkylaminodiazine or polyalkylaminotriazine, and (b) a polyphenyl ether in which the ratio of (a) to (b) is from 1:9 to about 9:1. The viscosity of the disclosed composition is substantially less than the Viscosity of either component.

THE INVENTION The present invention concerns new functional fluids and the use thereof.

The term functional fluid (lubricant fluid for machines) embraces fluids wvhich have the properties necessary for rnachines or apparatus to perform their function. For example, lubricants, hydraulic liquids, damping and brake fluids, dielectric fluids and heat-transferring agents, are included in this term [cf. Roger E. Hatton, Introduction to Hydraulic Fluids, Reinhold Publishing Corp., New York, 1962, page Very high demands are made of functional fluids such as are used in modern machines and apparatus which function at very high temperatures, e.g., gas turbine aircraft engines; for example:

(1) They must be liquid under the conditions for use and must be capable of forming a lubricant film on the most varied materials, in particular on metals.

(2) They :must be substantially stable to high temperatures and oxidative influences.

(3) They should not be corrosive and, above all, should not form any acid decomposition products.

(4) They should retain their lubricant properties over as large a temperature range as possible, i.e., their viscosity should be as independent as possible of the temperature.

(5) Their solidification point should be as loW as possible and, on the other hand, the boiling point should be as high as possible.

There are considerable difficulties in finding functional fluids which substantially meet all the above conditions.

Hitherto, polyphenyl ethers and polyalkyl melamines, among others, have been used as high boiling functional fluids. However, the viscosity of these compounds is too high for some purposes, particularly at low temperatures.

A functional fluid of great value having relatively low viscosity has now been found. It consists of a mixture of (a) Polyalkylamino diand/or triazines which melt at below 75 C. and preferably below 35 C., and

3,424,683 Patented Jan. 28, 1969 ICC (b) Polyphenyl ethers in a weight ratio of 1:9 to 9:1,

preferably 3:7 to 7:3.

The mixtures according to the invention have considerably less viscosity than the average values normally to be expected from the viscosities of the individual components forming the basis of the mixtures. According to the Lubricant Testing by E. G. Ellis, B. Sc., F. Inst. Pet. Scientific Publ. (Great Britain) 'Ltd., 1953, pp. 51-53, the logarithms of these average values should almost correspond to the arithmetical mean of the logaritms of the viscosities of the components.

As polyalkylamino door triazines which are suitable as component (a) in the mixtures according to the invention, principally those of Formula I are used.

In this formula:

X represents N or CH,

R represents hydrogen or an alkyl radical having 1 to 16 carbon atoms,

R represents an alkyl radical having 1 to 16 carbon atoms, and

R R R and R each represent an alkyl radical having 1 to 6 carbon atoms, the sum of all carbon atoms in all nitrogen substituents being at least 12.

Advantageously each of R R R R R and R represents an n-alkyl radical. X is preferably nitrogen; i.e., the compounds are polyalkylamino-l,3,5-triazines. They are described in French Patent No. 1,328,168. They can be obtained, for example, by reacting the 3 chlorine atoms of the cyanuric chloride, in steps, with the desired alkylamines by methods known per se.

Examples of such polyalkylamino-1,3,5-triazines are:

2-dimethyla-mino-4,6-bis-dibutylamino-1 ,3 ,5 -triazine, 2 diethylamino-4,6-bis-dibutylamino-1,3,5-triazine, 2,4,6-tris-diethylamino-1,3,5-triazine, 2,4,6-tris-dibutylamino-1,3,5-triazine, 2,4,6-tris-dihexylarnino-1,3,S-triazine, Z-(N-methyl-N-decylamino) 4 (N-methyl-N-butylamino)-l,3,5-triazine, 2-(butylamino 4 (dibutylarnino)-6-(diethylamino-, di-

decylaminoor -didodecylamino)-1,3,5-triazine, 2-dimethylamino-4,6-bis (N-methyl-N-butylamino)-1,3, S-triazine.

Polyalkylamino compounds of Formula I wherein X is CH, i.e., polyalkylaminopyrimidines, are obtained, e.g., by reacting in steps by methods known per se, the three chlorine atoms of the 2,4,6-trichloropyrirnidine with the desired al-kylamines.

Examples of such polyalgylaminopyrimidines are:

2-diethylamino-4,6-'bis-dibutylaminopyrimidine, or 2,4,6-tris-dibutylaminopyrimidine.

Naturally in the mixtures according to the invention, also mixtures of polyalkylamino diand -triazines of Formula I can be used as component (a).

Polyphenyl ethers which are suitable as component (b) in the mixtures according to the invention are, in particular, those of Formula II.

In this formula n represents 1 to 4, preferably 2 to 3. The phenyl rings can contain alkyl or alkoxy groups having, preferably, 1 to 20 carbon atoms; advantageously, however, they are unsubstituted.

Compounds wherein the oxygen bridges are in the mposition to each other and, principally, mixtures of isomeric polyphenyl ethers having a high content of components with ether linkages in the m-position, are particularly suitable as component (b) because mixtures according to the invention which contain them have a particularly low range at which they solidify. The polyphenyl ethers may be produced according to French Patent No. 1,394,304 and R. C. Gunderson and A. W. Hart, Synthetic Lubricants, The Dow Chemical Company, Midland, Mich., Reinhold Publishing Corp, London, and R. L. Hattan, Hydraulic Fluids," pp. 297-308 (same publisher).

The unexpected lowering of the viscosity mentioned above is attained in partciular at certain definite viscosity ratios between the two components of Formulae I and II of the mixture. As a rule, the quotient of the logarithms of the viscosities of the two components, measured in centistokes and each increased by 0.6, must be 0.7 to 1.4. Then viscosities of the mixtures according to the invention are obtained which are by 20% and more below the expected arithmetic mean values of viscosity and are usually, even by 510% or more, below the value of the component having the lower viscosity.

The new functional fluids are only slightly volatile oils. They have good thermostability and, at high temperatures such as are presented for gas turbine oils for aircraft engines, they form no noticeable amounts of acid decomposition products. Thus they have no or only a very slight corrosive action in practical use. In addition they only slightly swell plastics such as are used, e.g. for gasket materials. They can be applied within a wide temperature range, they have a good lubricating action, a low solidifying point and good stability to acid and alkali.

The functional fluids according to the invention can be used as multipurpose lubricants.

The new functional fluids are suitable for the lubrication .of hard surfaces because they form very adherent films thereon. For example, they are good lubricants for metals, silicates such as glass, and for other materials needing lubrication such as organic and inorganic high polymeric compounds.

The functional fluids according to the invention can be used alone or in admixture with other substances. In order to increase their heat stability to over 150 0., they can be mixed with antioxidants whereby their life becomes satisfactory even under increased oxidative conditions.

Such antioxidants are the usual homoor heterocyclic aromatic amines, hydroxyaryl and aminohydroxyaryl compounds and heterocyclic compounds having no free amino groups. They are used, preferably, in amounts of 0.01-5% by weight. (These and the following percentages with regard to additives to the mixtures according to the invention always refer to the total weight of the latter.)

Examples thereof are diphenylamine,

diphenylamines alkylated in the nucleus,

phenylnaphthyla-mines,

phenyl acenaphthenylamines,

4,4'--dinaphthylaminodiphenyl,

thiazolyl- (2) -naphthylamines,

N,N-diphenyl-p-phenylenediamine,

N,N'-dioctyl-p-phenylenediamine,

N,N-dicyclohexyl-p-phenylenediamine,

N-sec.butyl-N-phenyl-rrphenylenediamine,

N,N'-bis(' -aminopropyl)-p-phenylenediamine,

2,4-dimethyl-6-tert.butylphenol,

2,6-di-tert.butyl-4-ethyl phenol,

2,6-bis 1-methylcyclohexyl)-4-methyl phenol,

2,6-di-tert.butyl-4-dimethylaminomethyl phenol,

2,2-methylene-bis 4-methyl-6-te rt.butyl phenol),

2,2-thio-bis(4-methyl-6-tert.butyl phenol),

4,4 dihydroxy 2,2 dimethyl-S ,5 di-tert.butyl-diphenyl sulphide and -diphenyl disulphide,

2,6 bis (2-hydroxy-3-tert.butyl-5-methyl-benzyl)-4-methyl phenol,

2-tert.butyl-1-hydroxynaphthalene,

4,6-di-tert.butyl-5-hyd-roxy indane,

5-hydroXy-acenaphthene,

butyl pyrocatechol,

octyl gallate, butyl hydroxy anisol,

p-hydroxy-diphenylamine,

p-hydroxyoctylaniline,

p-hydroxy-N-y-aminopropyl aniline,

phenothiazine,

iminodibenzyl,

2-tert.octyliminodibenzyl,

5-ethyl-10,10-diphenyl phenosilazine,

6-methoxyor 6-ethoxy, or 6-ethyla-mino-2,2,4-trirnethyl- 1,2-dihydroquinoline or telomers thereof,

3hydroxy-7,8-benz0-1,2,3,4-tetrahydroquinoline,

tocopherol or dialkyl selenides.

Also, functional fluids according to the invention can contain high pressure additives such as phosphites, phosphates, sulphurised sperm oil, barium or calcium-mahogany sulphonates, anticorrosives such as sarcosines or benztriazoles, agents which lower the solidification point andif necessaryalso defoaming agents, e.g., those based on siliconeoil. All these additives are preferably admixed in amounts of about 0.5-5

The invention also concerns greases which are produced from mixtures as defined and thickeners. The latter are added in amounts of, preferably, about 10-50%. Examples of such thickeners are metal soaps, bentonite, phthalocyanines, violanthrones, etc.

In addition, the new synthetic functional fluids can also be mixed with usual functional fluids of other classes to attain special effects;

The following examples show the surprisingly low viscosity of the mixtures according to the invention compared with that of the individual components. The units of measure of the metric system are used therein. The viscosities are measured in centistokes.

TABLE-VISCOSITY OF MIXTURES OF POLYALKYLAMINO DI- R TRIAZINES WITH POLYPHENYL ETHERS Polyphenzall (21211918 of the Mixtures of polyalkylamino di Polyalkylamino dior triazines of the general formula gene rmula ohtriazines and polyphenyl e ers Ra\ /X\ R] (i) ii I Q R hi /N R;

C L; 0 R4- Ra l No. of carbon atoms Viscosity at Viscosity at Viscosity at Content of 100 F. 100 F. 100 F. polyphenyl No. Ex. X R; R; R R R R (375 C.) in n (375 C.) in (37.5" C.) in others in centistokes centistokes centistokes percent by weight N 2 2 4 4 4 4 103. 5 2 69. 6 50.0 60 N 1 1 4 4 4 4 68.8 2 69. 6 48. 5 50 N 2 2 2 2 2 2 73. 0 1 2 69. 6 46. 1 50 N 1 4 1 1 1 37.1 1 2 69. 6 35. 2 N 4 4 4 4 4 4 131. 6 1 2 69. 6 57. 6 70 N 6 6 6 6 6 6 105. 0 1 2 69. 6 56. 3 50 N 2 0 4 4 4 2 2 136. 6 l 2 69. 6 54. 0 70 N 1 1 4 1 2 4 7.62 1 4.31 4.75 N 4 4 4 4 4 4 131. 6 5 3 341. 0 113. 8 30 N 6 6 6 6 6 6 105.0 5 3 341. 0 97. 0 10 N 2 2 4 4 4 4 103. 5 6 3 341.0 100. 0 30 CH 4 4 4 4 4 4 38. 8 1 2 69. 6 36. 3 CH 4 4 4 4 6 6 112.0 1 2 69. 6 55. 7 30 CH 10 10 4 4 4 4 57. 9 l 2 69. 6 45. 3 CH 12 12 4 4 4 4 79. 9 1 2 69. 6 51. 3 45 CH 2 2 4 4 6 6 101. 0 l 2 69. 6 54. 7 30 CH 2 2 4 4 6 6 101. 0 5 3 341.0 96. 8 80 CH 4 4 4 4 6 6 112.0 5 3 341. 0 103. 0 80 1 3 Measured at 170 F. (76.7 C.)

The mixtures Nos. l-18 given above are suitable for greasing metal and glass surfaces.

Example 19.Production of a functional fluid containing antioxidant 98 g. of a mixture of polyalkylamino tn'azine and polyphenyl ether according to No. 1 of the above table are stirred with 2 g. of di-tert.octyl-diphenylamine as antioxidant until the latter has completely dissolved.

Compared with a mixture not containing antioxidant, the mixture obtained has increased stability to oxidation.

The other mixtures given in the above table can be made more resistent to oxidative influences in the same way.

If, instead of the 2 g. of di-terLoctyl-diphenylamine, 2 g. of one of the antioxidants given below are used and otherwise the procedure given is followed, then the stability to oxidation of the polyalkylamino diand tri-azine/ polyphenyl ether mixture is likewise increased:

Di-dodecyl selenide,

1,1,3-tri(2'-methyl-4'-hydroxy-5'-tert.butylphenyl)- butane,

2,6-di-tert.butyl-4-methyl phenol,

2-tert.octylimino-dibenzyl, or

5-ethyl-10,l O-diphenyl-phenosilazine.

Example 20.Production of a functional fluid containing anticorrosive 99.8 g. of a mixture of polyalkylaminotriazine and polyphenyl ether according to No. 1 of the above table are mixed with 0.2 g. of benztriazole. Compared with mixture No. 1 not containing this active substance, the mixture obtained has a less corrosive action particularly on copper and alloys thereof.

4 p-Bisphenoxybenzene.

5 Mixture of about 65% of m-bis(m-phenoxyphenoxy)-benzene, 30% of m-[(m-phenoxyphenoxy)-(p-phenoxyphenoxy 1-benzene and of m-bis(p-phenoxyphenoxy)-benzene.

Similar results are obtained with the other mixtures given in the above table.

Example 21.Production of a functional fluid containing an agent to lower the solidification point 97 g. of a mixture of polyalklaminotriazine and polyphenyl ether according to No. 1 of the above table are stirred into a homogeneous mixture with 3 g. of polymeric methacrylic acid ester, in particular with poly-2- ethylhexylmethacrylate (HP 825, Rohm & Hass Co., Philadelphia, U.S.A.). This mixture has a lower solidification point than one not containing this active substance.

Similar results are also obtained with the other mixtures given in the above table.

Example 22.Production of a functional fluid containing a high pressure additive 98 g. of a mixture No. 11 of the above table are stirred with 2 g. of tricresyl phosphate. The mixture obtained withstands high pressure better than a mixture not containing this high pressure additive.

Similar results are obtained with the other mixtures given in the above table.

Example 23.Production of a functional fluid containing antioxidant and anticorrosive When 97.8 g. of mixture of polyalkylaminotriazine and polyphenyl ether according to No. 1 of the above table are mixed with 2 g. of di-tert.octyl-diphenylamine as antioxidant and 0.2 g. of benztriazole as anticorrosive, then a functional fluid is obtained which is less sensitive to oxidation and has less corrosive action than the corresponding functional fluid not containing the active substances mentioned.

Similar results are obtained with the other mixtures given in the above table.

Example 24.Production of a functional fluid containing antioxidant, anticorrosive and high pressure additive When 94.8 g. of mixture of polyalkylaminotriazine and polyphenyl ether according to No. 1 of the above table are mixed with 2 g. of di-tert.octyl'diphenylamine as antioxidant, O.2 g. of benztriazole as anticorrosive and 3 g. of tricresyl phosphate as high pressure additive, then a functional fluid is obtained which is less sensitive to oxidation, has a less corrosive action and which can withstand higher pressures than the corresponding functional fluid not containing the active substances mentioned.

Similar results are obtained with the other mixtures given in the above table.

Example 25 The use of the mixture of compounds of Example 1 of the table for the production of greases is shown in the following example.

8 g. of copper phthalocyanine, 4 g. of the mixture of Example 1 and 40 cc. of benzene are stirred very quickly in an Ultraturax mixer for minutes. Another g. of the mixture of Example 1 are then added. Fast stirring is continued for another 45 minutes.

The homogeneous mass obtained is worked up on a glass surface with a spatula until the benzene has evaporated. The mass obtained is heated for 2 hours at 150 and after cooling is again worked up with a spatula. The product formed is a soft grease with good thermostability.

Similar results are obtained with the other mixtures given in the above table.

The synthesis and boiling points of the polyalkylaminotriazines Nos. 1-11 mentioned in the above table are given in French Patent No. 1,328,168. The diazines used in this invention are produced as described in French Patent No. 1,413,722.

The boiling points of the polyalkylaminodiazines 12-18 of Formula Ia We claim: 1. A functional fluid comprising: (a) a compound of the formula:

wherein X is N or CH;

R is hydrogen or an alkyl radical having 1 to 16 carbon atoms;

R is an alkyl radical having 1 to 16 carbon atoms;

and

R R R and R each is an alkyl radical having 1 to 6 carbon atoms, the sum of the carbon atoms of all nitrogen substituents being at least 12, and

(b) a polyphenyl ether compound of the formula:

wherein n is an integer of 1 to 4, and in which the phenyl rings may be substituted with alkyl or alkoxy groups, the weight ratio of the compound of (a) to the compound of (b) is 1:9 to 9:1. 2. A functional fluid as claimed in claim 1 wherein X is N.

R CH

y 3. A functlonal fluld as claimed in claim 1 1n which the fi weight ratio of the compound of (a) to the compound of R N N R; (b) is 3:7 to 7:3.

4. A functional fluid as claimed in claim 1 in which the quotient of the logarithms of the viscosities of the com- R4N R3 (Ia) ponents (a) and (b) of the fluid, measured in centistokes,

are: and it increased b 0.6, is 0.7 to 1.4.

R4 R5 R0 B.P.,C.

n-Butyl n-Butyl n-Butyl 100-4 (0.3 ton).

d .d0 do 217-22 (0.3 tOIl). n-Decyl do ...do 250-70 (anus-0.005 torr). n-DodecyL- n-Dodecyl "do.-. do d0. .do 252-8 (0.004 ton). n-Hexyl n-Hexyl d0 do Ethyl Ethyl 200-2 (0.3 ton).

References Cited UNITED STATES PATENTS 3,250,708 5/1966 Dazzi et al 252- XR 3,290,249 12/1966 Wilson 252-52 XR 3,290,307 12/1966 Keller et al. 25250 XR 3,325,496 6/1967 Critchley et al. 252-50 XR PATRICK P. GARVIN, Primary Examiner.

US. Cl. X.R. 

